A cutting accessory is an implement that typically removably attached to a powered surgical handpiece to perform a surgical procedure. One cutting accessory used to perform a surgical procedure is a bur. A bur generally comprises a head formed from rigid material, typically metal, shaped to have a number of flutes. The flutes are formed to define cutting edges. The cutting edges are typically designed to cut hard tissue, such as bone or cartilage. A shaft extends proximally from the head. A proximal end of the shaft often has a feature that facilitates locking the shaft to the powered handpiece. Actuation of the handpiece results in rotation of the bur. During a surgical procedure, the head of the bur is placed against a surgical site where a section of tissue is to be removed. The rotating cutting edges excise tissue away from the surgical site. Burs of various shapes and sizes are used in procedures such as orthopedic surgery, neuro and spinal surgery, ear nose and throat surgery and in other surgical procedures to selectively remove a section of tissue.
Conventional burs work well for the general purpose of removing tissue. Nevertheless, a problem associated with some burs is excessive noise/vibration and possibly chatter. Chatter is the escalation of the noise/vibration of the bur to a resonance level. Chatter is often visualized as a relatively large spike or group of spikes in the amplitude of the noise/vibration experienced by a bur. Some prior art burs exhibit better characteristics than others with respect to noise/vibration and chatter. However, when noise/vibration and chatter are minimized, cutting efficiency is often reduced. One such bur is the subject of the Applicants’ Assignee's U.S. Patent Pub. No. US 2008/0132929 A1/WO 2007/010389 A1, SURGICAL BUR WITH ANTI-CHATTER FLUTE GEOMETRY, which is explicitly incorporated herein by reference. When cutting efficiency is reduced, the head of the bur must make additional rotations to cut the same amount of material thereby generating more heat. Thus, there is a need in the art for a bur that reduces excessive noise/vibration while preventing undesirable heating of the head of the bur.